Carbon-carbon friction clutches of this type, used mainly at present in competition vehicles, have many advantages over conventional clutches, in particular very high resistance to large stresses, low wear under high stress and reduced mass and inertia.
However, these clutches are subject to the problem that the clutch comes free less well than conventional clutches with organic linings.
Thus, two supplementary structural driving plates, on the flywheel side and the thrust plate side, are needed in such clutches since the friction only acts at the carbon-carbon interfaces. As a result there are two additional regions of play in the disengaged position.
Considering the example of a conventional single plate clutch, the friction interfaces are cast iron-to-organic material and the play is distributed between the flywheel/driven plate interface and the driven plate/thrust plate interface.
In the case of clutch with structural plates and called a "single-plate" clutch by analogy, the play is distributed over four interfaces, namely the flywheel/first driving plate non-clutching interface, the first driving plate/driven plate clutching interface, the driven plate/second driving plate interface and the second driving plate/thrust plate interface.
With the same total play only half as much play results at the two friction clutching interfaces and, as a result, there is additional wear and residual friction leading to unsatisfactory disengagement.
The object of the invention is to provide a structural plate clutch which, apart from the inherent value of these plates, especially carbon-carbon plates, namely being made in one piece, and their inherent properties which are considerably superior to those of conventional plates, has means referred to as packing-up which are reliable and simple, while comprising a limited number of components, which enable the play to be better distributed.